1. Field of the Invention
The present invention relates to electrical connectors and, more particularly, to a push-pull type electrical connector.
2. Description of the Related Art
FIG. 8 shows part of a conventional push-pull type electrical connector. A connector 50 comprises a housing body 51 having a front tubular section 52. A sleeve 54 is biased forwardly by a coil spring 53 along the tubular section 52. Circumferential projections 55 and 56 are provided at the front end and an end portion of the tubular section 52. A circumferential projection 57 is provided on the inside middle portion of the sleeve 54 to determine the most forward position of the sleeve 54 which is biased by the coil spring 53 and define an annular space 59 between the sleeve 54 and the tubular section 52. A circumferential recess 58 is provided on the inside front end of the sleeve 54 at a position corresponding to the circumferential projection 55 of the tubular section 52.
Another connector 60 comprises a housing body 61 having an outer tubular section 62 to form an annular receiving space 63 for receiving the tubular section 52 of the connector 50 while the outer tubular section 62 enters the annular space 59. The outer tubular section 62 has a pair of axial slits and a circumferential slit 64 to form a cantilevered flexible arm 65 which has an inward projection 66 at the front free end.
When the connector 60 is plugged into the connector 50 in the direction of an arrow in FIG. 8, the outer tubular section 62 enters the annular space 59 of the connector 50. The inward projection 66 of the flexible arm 65 is pushed outwardly by the circumferential projection 55 to flex the flexible arm 65, which pushes rearwardly the sleeve 54 at the shoulder of the circumferential recess 58 against the bias of the coil spring 53. When the inward projection 66 passes over and engages with the circumferential projection 55, the flexible arm 65 returns to the normal position. Then, the sleeve 54 returns to the front position so that even if the flexible arm 65 receives an external force in the radial direction, it cannot be flexed outwardly owing to the sleeve 54, thus locking the plugging of the connectors.
To separate the connectors, the sleeve 54 is pulled rearwardly against the coil spring 53 while the other connector 60 is pulled out of the connector 50.
However, the conventional connectors are too long in the plugging direction and difficult to handle. The flexible arm 65 of the other connector 60 must be sufficiently flexible to provide a predetermined amount of flexure. In order to assure engagement between the connectors 50 and 60, the engaging projections 55 and 66 must be large. In order that the inward projection 66 passes the circumferential projection 55, the flexible arm 65 must be long, leading to the long connectors 60 and 50.
Upon plugging, the sleeve 54 of the connector 50 must retreat to a large extent, which means that the operator cannot work by holding both the connectors 50 and 60 because if the operator holds the sleeve 54, the sleeve cannot retreat.